Dental caries prevalence in children with cleft
lip/palate aged between 6 months and 6 years in the West of
Scotland.

Abstract:

AIM: To compare the prevalence of dental caries in children with
cleft lip/palate with national data at the same age. METHOD: Ethical
approval was granted from the West of Scotland Ethics Committee.
Children attending the Oral Orthopaedic Clinic were examined for caries
according to the criteria of the British Association for the Study of
Community Dentistry (BASCD) by two trained and calibrated examiners (KB,
RW). Subjects were divided into five age groups: 0.5-1.49; 1.5-2.49;
2.5-3.49; 3.5-4.49 and 4.5-6.0 years. Mean dmft scores were compared
with available national data (National Dental Inspection Program of
Scotland) for nursery [NDIP 3-year-old survey 2008, unpublished] and
5-year-old children in Scotland [NDIP, 2008]. RESULTS: 209 subjects were
examined (participation rate of 87.4%); 45.9% were female, 54.1% male;
21 children (10%) had a recognised syndrome and were reported
separately. Cleft Palate (CP) was the most commonly occurring cleft in
both syndromic and non-syndromic groups, followed in decreasing numbers
by Unilateral Cleft Lip and Palate (UCLP), Bilateral Cleft Lip and
Palate (BCLP), Unilateral Cleft Lip (UCL) and Bilateral Cleft Lip (BCL).
The only age group with a significantly higher level of dental caries
compared with national data was the 4.5-6.0 year-olds where only 37.2%
of the children with clefts were caries free compared with the national
figure of 57.7% (p=0.004). This same age group had a mean dmft for the
cleft group of 3.24 compared with 1.86 nationally. The other age groups
had similar dmft and percentages of subjects caries free compared with
the national data. The differences did not reach significance. Caries
was more common in the anterior teeth of the youngest two age groups,
but in the posterior teeth of the two oldest age groups. CONCLUSION: By
the age of 4.5 years, children with cleft lip/palate in the West of
Scotland have significantly more caries than their non-cleft peers.

Orofacial clefts are the most commonly occurring craniofacial
defect with an average prevalence of 1.2/1000 live births [Mossey et
al., 2007]. Children born with an orofacial cleft (CLP) have a high
burden of care throughout their childhood. Most can expect: at least one
general anaesthetic for surgery; speech therapy assessments and
treatment; dental and orthodontic treatment; and possible psychological
problems associated with the appearance of their cleft.

Papers investigating the prevalence of caries in cleft children and
adults have variously reported a higher prevalence of caries in children
with CLP [Dahllof et al., 1989; Bokhout et al., 1997; Paul and Brandt,
1998; Chapple and Nunn, 2001; Hewson et al., 2001; Ahluwalia et al.,
2004; Kirchberg et al., 2004; Al-Wahadni et al., 2005; Stec-Slonicz et
al., 2007; Mutarai et al., 2008], a lower prevalence [Gregg et al.,
1999] or have concluded that there is no evidence to suggest a
difference [Lausterstein and Mendelsohn 1964; Parapanisiou et al.,
2009]. No studies investigating the prevalence of caries in CLP children
have been carried out in Scotland to date.

Two papers, Wong and King [1998] and Hasslof and Twetman [2007],
conducted systematic reviews of the literature. Hasslof and Twetman
found potential problems with the control children used, caries
diagnosis methods and a lack of data on 'social class
indicators'. Wong and King concluded that small sample sizes,
varying methods of presenting caries results, a lack of suitable control
groups and a wide age range constitute some of the methodological
difficulties in carrying out research in this field. They recommended
that caries data should be presented by region and that this 'would
give a comprehensive picture of caries experience that is suitable for
future comparisons'.

The aim of this study was therefore to compare the prevalence of
caries in cleft children in the West of Scotland with national data from
non-cleft children of the same age taking into consideration the
recommendations of the review papers quoted above. It is hoped that this
data will improve the evidence base in the West of Scotland and provide
a database for comparison in any future studies.

Materials and Methods

Study Subject. All children with CLP, between the ages of 6 months
and 6 years, in the West of Scotland were invited to attend the Oral
Orthopaedic Prevention Clinic at Glasgow Dental Hospital and School. The
children receive a dental examination and preventive dental advice was
given to parents regarding toothbrushing and diet. All these children
were eligible to take part in this study.

Demographic Data. The demographic data collected from the
subject's clinical notes comprised: name; gender; date of birth;
age; full postcode; side and type of cleft. After data collection, study
subjects were allocated a study number to ensure anonymity when entered
into the password-protected database on an encrypted computer. Study
subjects were divided into the following age groups for analysis:
0.5-1.49 years; 1.5-2.49 years; 2.5-3.49 years; 3.5-4.49 years; and
4.5-6.0 years.

The postcode of the parents/carers home was used to allow the
degree of deprivation to be analysed using the Scottish Index of
Multiple Deprivation (SIMD) system. A UK postcode represents a street, a
part of a street or a small village. Each postcode encompasses a maximum
of 80 properties. SIMD uses the full postcode and converts this into a
measure of deprivation. SIMD 2006, the version available during the
study timeframe, combines information regarding current income,
employment, health, education, skills and training, housing, geographic
access and crime. These seven domain scores are weighted to provide an
overall score for each data zone. The Scottish Government website
(www.scotland.gov.uk/topics/statistics/SIMD) provides a
'lookup' file which enables a postcode to be entered and
converted into its SIMD score. There are five categories or quintiles
ranging from 1 (least deprived) to 5 (most deprived). The SIMD data was
analysed to determine whether deprivation was associated with the
presence of a cleft and to see whether this study replicated the link
between increasing deprivation and increasing prevalence of caries found
in previous studies.

Dental caries registration. Caries was recorded as both dmfs and
dmft according to BASCD criteria [Mitropoulos et al., 1992; Pitts et
al., 1997] to the D2 level i.e. caries extending into dentine. Clinical
examinations form an integral and routine part of the Oral Orthopaedic
Prevention Clinic at Glasgow Dental Hospital and School and the study
subjects were examined using a dental light, mirror and CPITN probe when
reclined in the dental chair.

The study clinicians were trained and calibrated to BASCD standards
prior to the start of the study. The training component involved an
illustrated lecture and discussion session on how to record the caries
present in accordance with criteria set down by BASCD. Thereafter a day
of clinical training and calibration was held to determine whether
either dentist's lay records within the acceptable range of
agreement. The Kappa scores were 1.0 for both KB and RW.

Dental caries as dmft and dmfs scores were calculated for each
study subject. Within each age group the following were calculated in
addition:

The Dental Care Index is a measure of how much of any existing
caries has been restored expressed as a percentage. It takes no account
of any extracted teeth and is calculated by ft/dmft x 100. The mean dmft
was calculated for each different cleft type.

Dental caries comparisons. The comparisons for this study
population were the 2008 National Dental Inspection Program of Scotland
(NDIP) figures for the appropriate age matched groups. NDIP is a yearly
epidemiological monitoring programme of the dental health of Scottish
school children in mainstream school. Each year all children in Nursery
School (mean age 3 years) and either Primary One (mean age 5 years) or
Primary Seven (mean age 12 years) are inspected according to BSASCD
criteria. In 2008 the 5-year-old children and Nursery children were
inspected. The results of these dental inspections are available on-line
at www.scottishdental.org/index.aspx?o=2153.

The 3-year-old NDIP subjects had an age range of 2.5 years to 4.5
years and were used as the non-cleft comparison for the 2.5-3.49 and
3.5-4.49 years study groups. The 5-year-old NDIP subjects had an age
range of 4.5 to almost 6 years and were used as the non-cleft comparison
for the 4.5-6.0 years study group. The study clinicians were trained and
calibrated to the same BASCD standards to ensure that valid comparisons
could be made between NDIP and study data.

Statistical Analysis. This was a mainly descriptive study using
means and proportions with standard deviation and confidence intervals
where appropriate. The results were analysed using Minitab 15 English
and SPSS 15.0 for Windows. Differences between study and comparator data
were analysed using Fisher's exact test and statistical
significance was reported at a 5% level (p [less than or equal to]
0.05).

Results

Study Subjects. 209 subjects were examined of whom 21 (10%) had
been diagnosed with a syndrome or an inherited chromosomal abnormality
and were excluded from the study. Of the 188 study subjects 45.9% were
female and 54.1% were male. Isolated cleft palate (CP) accounted for the
majority of the clefts present (45%), followed in decreasing numbers by
Unilateral Cleft Lip and Palate (UCLP) 26%, Bilateral Cleft Lip and
Palate (BCLP) 11%, Unilateral Cleft Lip (UCL) 7 % and Bilateral Cleft
Lip (BCL) 1%.

The Scottish Index of Multiple Deprivation (SIMD) divides the
population into five equal 'quintiles', and as such, one would
expect 20% of the population to be represented in each quintile. In this
study there was a linear trend of increasing proportions of subjects
within each category from the least deprived (13.9%) to the most
deprived quintile (31.1%) and less than an expected 20% within SIMD
category 1 (least deprived) whilst there were more than the expected 20%
in SIMD category 5 (most deprived). When comparing this with data for
5-year-olds in Greater Glasgow the figures showed a broadly similar
distribution. Approximately 60% of both the study and general population
of 5-year-olds were present in the two most deprived SIMD quintiles.

Dental caries data. The mean dt, mt, ft and dmft scores with
standard deviations (SD) for each age group were 1.5-2.49 years, 0.49
(2.08); 2.5-3.49 years, 1.03 (2.70); 3.5-4.49 years, 0.94 (1.98);
4.5-6.0 years, 3.24 (4.43). The dt, mt, ft and dmft scores with 95% CI
for each study age group are shown in Table 1. The mean dmft (SD) for
those subjects who had a dmft score of greater than zero in the study
age groups was: 1.5-2.49 years, 5.5 (5.19); 2.5-3.49 years, 4.0 (4.21);
3.5 - 4.49 years, 2.9 (2.6); 4.5 - 6.0 years, 5.16 (4.63). The
percentage of each age group who were caries free is shown in Table 2.
The proportion of caries in anterior and posterior teeth by tooth and
surface detail is shown in Figure 1 and 2.

Dental caries by cleft type. The mean dmft scores for each cleft
type varied by type. Subjects with BCLP had the highest mean dmft figure
of 2.77 (5.98). This was followed by CP 1.16 (2.32), UCLP 0.81 (1.84)
and UCL 0.57 (1.28). Numbers in each cleft type group were too small to
allow valid statistical comparison.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

Dental Care Index. The Dental Care Index was not applicable in the
0.5-1.49, 1.5-2.49 and 2.5-3.49 year study groups as no restorations had
been carried out at all. The Dental Care Index for the 3.5 - 4.49 years
group was 10.5 and for the 4.49-6.9 years group was 10.9.

Comparator Data. The available comparator figures for the
percentage of subjects caries free were those for 3-year-olds [NDIP,
2008] and 5-year-olds [NDIP, 2008]. These national figures are shown in
Table 1. In the present study the 4.5-6.0 year-old age group had
significantly fewer subjects who were caries free compared with their
non-cleft peers (p=0.004). The comparison of study mean dmft with the
2008 NDIP results for the same age groups, where available, is shown in
Table 3.

Unfortunately the standard deviations of the mean dmft figures were
not available for the national data. This prevented assessment of
significance between study and national groups. The Dental Care Index
(ft/dmft x100) for the 4.5-6.0 year age group was 10.9.

Discussion

Although the number of study subjects (209) was relatively low this
represented the majority of the available CLP population of the
appropriate age range in the West of Scotland. Of the 289 subjects who
would qualify for the study from birth data, nine died in infancy, 40
lived at a some distance from Glasgow and receive their preventive and
continuing care nearer to home and one had moved away from the area
leaving 239 potential subjects. Therefore the study participation rate
was 87.4%. Of the 30 potential subjects who did not participate, 13
failed to attend at least one appointment during the period of the
study. The remaining 17 were born in 2008 and were barely six months old
so that their initial appointment would have been just after the end of
the study period.

In order to give a more accurate picture of the prevalence of
dental caries, and to try to alleviate the potential problem of a wide
age range [Wong and King, 1998], subjects were divided into yearly age
bands from 6 months of age up to 6 years of age.

The gender ratio found in this study was almost identical to those
reported by two previous Scottish studies. Clark et al. [2003] reported
45% female and 55% male, and Womersley and Stone [1987] reported 45.3%
female and 54.6% male. The proportion of CLP types in this study was
similar to those of Chapple and Nunn [2001] in their North of England
study who also found that the majority presented with CP, followed in
turn by UCLP and BCLP combined and UCL. Conversely, Ahluwalia et al.
[2004] in the South of England reported that UCLP presented most
commonly, followed in turn by BCLP, CP and UCL. The number of subjects
in this study with a syndrome (10%) lies between the 6.1% reported by
Dahllof et al. [1989] and 15.5% by Hasslof and Twetman [2007].

Dental Caries Data. Unfortunately the only two Scottish studies
involving the CLP population examined the distribution of the different
types of cleft and did not investigate dental caries. Regarding the
percentage of subjects with no caries Chapple and Nunn [2001] reported
that 63% of their 4-year-old cleft subjects in the Newcastle area of
England were caries free, a figure that is slightly lower than the
4-year-olds in this study. Bokhout et al. [1996] reported that 74% of
the 2.5-year-old Dutch study subjects were caries free, again a similar
figure to that found in this study. Hewson et al. [2001] reported that
22% of their Irish cleft subjects were caries free. However this was a
figure for the whole study population that ranged in age from 18 months
to almost 17 years. Paul and Brandt [1998] also reported data for a
wider age range in their study conducted in Billericay, England. 78% of
the 41 subjects in their 3-5 year age group were caries free.

The only study reporting a significantly higher percentage of CLP
children caries free was that of Gregg et al. [1999]. Those authors
reported that 50% of their 5-year-old subjects were caries free. This
figure was achieved following specialist paediatric dental intervention
for the CLP children, including preventive advice and restorative care.

In our study the 0.5-1.49, 1.5-2.49, 2.5-3.49 and the 3.5-4.49 year
age groups had similar percentages of subject who were caries free
compared with the National data from NDIP, [2008]. The differences did
not reach significance. However, the 4.5-6.0 year age group had 20%
fewer caries free cleft children when compared with their Scottish
non-cleft peers (p = 0.004). When considering the 2008 NDIP figures for
the Greater Glasgow and Clyde (GGC) health board area alone, then 27%
fewer cleft children were caries free (p = 0.01).

Mean dt, mt, ft and dmft scores. Studies investigating caries in
cleft children have been undertaken in many varied geographical
locations over a long period of time. These, together with the fact that
many differing thresholds for the diagnosis of caries have been
employed, makes valid statistical comparisons with many study results
impossible. In most studies considering dental caries in CLP children,
the levels of caries were found to be higher in children with a cleft
compared with the unaffected population [Dahllof et al., 1989; Bokhout
et al., 1997; Paul and Brandt, 1998; Chapple and Nunn, 2001; Hewson et
al., 2001; Ahluwalia et al., 2004; Kirchberg et al., 2004; Al-Wahadni et
al., 2005; Stec-Slonicz et al., 2007; Mutarai et al., 2008].

Age group comparisons. For the age group 0.5-1.49 years no other
studies found have reported dmft for this age group of cleft children.
In the age group 1.5-2.49 years the mean dmft for this study group was
0.49. Although Ankola et al. [2005], reported a much higher D3 dmft of
6.57 for the 2-year-old cleft children in India, this must be viewed in
relation to the generally higher prevalence of caries in India.

The mean dmft in the age group 2.5-3.49 years was 1.03. Bokhout et
al. [1996] have reported a lower dft of 0.59. Ankola et al. [2005],
reported a higher mean dmft of 3.95 for the 3-year-old children in their
study. When compared with the NDIP results for the 2008 inspections of
nursery-aged children, the mean dmft figures are very similar (NDIP
0.97, our study 1.03).

In the age group 3.5-4.49 years Chapple and Nunn found a mean dmft
of 1.3 for the 37% of the 4-year-old cleft children with dental caries
in their 2001 study. Both these figures are slightly higher than our
mean of 0.94 for our 3.5-4.49 age group. This study took place in
Newcastle, England, and although it used the D3 threshold of diagnosis,
it was carried out in 2001, since when there have been significant
reductions in the incidence of caries in both England and Scotland. In
addition a large proportion of the children in the Newcastle study will
have been receiving fluoridated water.

When compared with the NDIP results for the 2008 inspections of
nursery-aged children, the mean dmft figures are virtually identical
(NDIP 0.97, our study 0.94) showing that there is little difference
between children with a cleft and their non-cleft peers in the 3.5-4.49
age group.

Considering the age group 4.5-6.0 years the mean dmft for this
group was 3.24. This was a large increase in the prevalence of caries
from a mean of 0.93 in the 3.5-4.49 year age group. When compared with
the NDIP results, the mean dmft in our study of 3.24 was greater than
that of the general population at 1.86 [NDIP, 2008]. CLP children in
this age group have an average of 1.38 more carious teeth than their
non-cleft peers of the same age. This is certainly a clinically
significant difference even although we have been unable to analyse the
significance statistically. When compared with the NDIP, [2008] data for
the Greater Glasgow and Clyde area, whose mean dmft for 5-year-olds was
2.07, the CLP study children had 1.17 more carious teeth.

Mean dmft scores for each CLP type. When looking at caries and CLP
type, the sample sizes within each cleft type were too small to allow
valid statistical analysis of the mean dmft figures. But generally the
results showed that subjects with more severe cleft types had a greater
prevalence of caries.

Mean dmft where dmft > 0. In the 4.5-6.0 year age group the mean
dmft for those subjects who did have caries (dmft >0) was 5.16,
higher than the NDIP [2008] figure of 4.39. Although 0.77 more teeth
with caries was a clinically significant difference it was not possible
to test statistical significance, as the NDIP standard deviation figures
were again unavailable.

Distribution of dental caries between anterior and posterior teeth.
It was thought interesting to see whether the caries in the study
subjects was mainly on the anterior teeth around the cleft site [Bokhout
et al., 1996; Bokhout et al., 1997] or whether it was distributed evenly
between the anterior and posterior teeth. With regard to both tooth and
surface detail, the 1.5-2.48 and 2.5-3.49 age groups both presented with
more caries in the anterior teeth. In the 3.5-4.5 age group the caries
was distributed evenly between anterior and posterior teeth. The 4.5-6.0
age group had more caries in the posterior teeth. An explanation for
this could be the eruption pattern of the primary teeth. It may be that
the anterior teeth are more carious in the younger age groups because
they have been erupted for a longer time and that by the 3.5-4.49 age
group the posterior teeth have been exposed to the oral environment for
long enough for caries to develop.

Dental Care Index. The Dental Care Index of 10.9 found in the
4.5-6.0 year age group compared favourably with the National Care Index
of 9.68 [NDIP, 2008]. No other national Dental Care Index figures were
available for comparison. Analysis of the Dental Care Index (ft / dmft x
100) showed that cleft subjects with high dmfs/t scores were more likely
to have a high ms/mt score--i.e. it was more likely that caries would be
treated by extraction rather than restoration.

Dental caries and deprivation (SIMD). The relationship between
caries and deprivation levels was confirmed in this study where
increasing deprivation was associated with increasing levels of caries.
When comparing the proportion of study 5-year-olds in each SIMD quintile
to the proportion of 5-year-olds in the Greater Glasgow and Clyde area
in each SIMD quintile, there was a similar trend towards increased
numbers in the two most deprived quintiles. Unfortunately the numbers
were too small to make statistical analysis reliable. Nevertheless,
descriptively it seems that there was not a higher level of deprivation
within the CLP study group. It is tempting to conclude that the
increased prevalence of caries in the CLP study children in the 4.5-6.0
age group was due to the presence of a cleft. However without
statistical evidence no firm conclusions can be drawn as to whether the
presence of a cleft is a significant causal factor in the development of
caries.

The results of this study indicate that relying on General Dental
Practitioners for targeted dental caries prevention, as has been the
case to date, appears to be insufficient to maintain the child CLP group
at national parity and that this population would benefit from
specialist treatment and being seen more frequently in a specialist
centre.

Conclusion

By the age of 4.5 years, CLP children in the West of Scotland have
significantly more caries than their non-cleft peers. This study shows
that the current regime of follow up at intervals of more than 6 months
is insufficient and the CLP children should be seen more frequently and
given treatment within a specialist centre. The aim is now for 4 monthly
recalls with a zero tolerance policy for the treatment of early dental
caries that will be undertaken by specialist paediatric dentists. With
these new provisions we hope to reduce the burden of dental caries in
the child cleft population in the West of Scotland.

Acknowledgements

This paper is based on a presentation that was a poster prize
winner of EAPD/BSPD Young Researcher at the Congress of the EAPD held in
Harrogate, England, June 2010. Ethical approval was granted by the West
of Scotland Ethics committee. The support of the members of the West of
Scotland Cleft team is gratefully appreciated.